The present invention relates to a prefabricated white chamber structure.
The white chamber structure according to the present invention has been specifically designed for the food industry and the electronic, pharmaceutical, hospital, medical, optical fields.
As is known, a lot of enforcing Rules, mainly with respect to food safety, compel makers to preserve a desired quality of the food product by controlling the environmental air quality and properly managing the temperature and relative humidity or moisture levels, as well as the pressure difference in the rooms in which the food processing operations are performed.
As is further known, a “white chamber” is a temperature, moisture, and particle concentration controlled room.
The air purity in the herein disclosed white chambers is classified by the ISO 14644 and subsequent standards, depending on a maximum number of particles having a diameter of 0.5 microns contained in a cubic meter of air.
The above standard defines the following environmental classes:
ISO 3 classmax contents of 35particles/m3ISO 4 classmax contents of 352particles/m3ISO 5 classmax contents of 3,520particles/m3ISO 6 classmax contents of 35,200particles/m3ISO 7 classmax contents of 352,000particles/m3ISO 8 classmax contents of 3,520,000particles/m3ISO 9 classmax contents of 35,200,000particles/m3
The ISO 3 class provides the highest air purity level.
The class is normally detected in a rest condition, that is in a finished work environment, in a ready to use condition with the production machines installed and switched on, but without operators and products in the working environment.
The requirements of a white chamber are as follows:                A filtering of air to be introduced into the working environment by a progressive system of increasingly efficient filtering barriers, up to a use of HEPA/ULPA absolute filters, with a minimum picking up efficiency of H13 99.95%-H14 99.995% (DOS test).        An overpressure of the working environment or room compared to adjacent processing rooms, in order to allow the air flow to be always oriented from the cleanest environment to the progressively less clean environment.        An environment air flow-rate, that is the air/hour volumes required to dilute polluting powders and hold a desired class. The cleaner should be the environment, the higher will be said volumes/hour.        The air flow within the processing room is of a conventional/turbulent type (to meet the ISO 7÷ ISO 8 classes). The flow being of a laminar type to meet the ISO 5 class.        Room cleaning: consists of designing the white chamber both to provide easily washable surfaces, without zones holding dirt, and studying the personnel and product movement paths to prevent the classed zones from being polluted.        
The objective of the white chamber for the food processing industry, and in a specific case of cutting and/or packaging and producing rooms, is to protect the air exposed food product from any risk of pollution, while minimizing its contamination, and holding constant and improving the end quality of the product while extending its shelf life.
In order to achieve a proper protection, without affecting the overall volume of the room, it would be possible to provide, in that zone in which the product is maximally exposed to pollution, a closest protection, the so-called “clean zone”, by providing a laminar flow designed to affect by air the product up to the packaging of the latter; in this manner, on the product it would be possible to achieve a cleaning class even better than the ISO 5 class.
The structures and civil works necessary to assure the required cleaning, hygienic, safety and quality properties, currently requested by the market, both in an industrial environment, for example in making or feeding meats, cuttings, packagings and in the commercial field, of cutting, packaging, and selling products on the processing site with variously fed products, are currently made with long operation times and high making costs.
Another drawback of prior structures is that the available spaces are not always sufficiently large and properly arranged.